[Prokaryotic expression and detective application of the main antigenic region of VP2 protein of Aleutian mink disease parvovirus].

To research safer diagnosis antigen for ADV, the main antigenic region VP2a and VP2b gene of ADV were obtained by restriction digestion of the recombinant plasmids pMD-VP2a and pMD-VP2b. Then the genes were respectively cloned into pMAL-c2 to get two prokaryotic recombinant plasmids pMAL-VPa and pMAL-VPb. The target genes were successfully expressed in the host cell TB1 when induced by IPTG. The Western blot analysis proved the recombinant proteins have good antigenic. The recombinant proteins were purified by KCL dyeing method, and were used as antigen to establish VP2-CIEP for AD diagnoses. The detection result shared 94.3% identity with that of CIEP. The results reported here show that VP2-CIEP is highly sensitive and specific and can benefit the research on the serodiagnosis to AD.

Epidemic of wild-origin H1NX avian influenza viruses in Anhui, China.

BACKGROUND: As the natural hosts of avian influenza viruses (AIVs), aquatic and migratory birds provide a gene pool for genetic transfer among species and across species, forming transient "genome constellations." This work describes the phylogenetic dynamics of H1NX based on the complete molecular characterization of eight genes of viruses that were collected from 2014 to 2015 in Anhui Province, China. METHODS: Hemagglutination and hemagglutination inhibition tests were used to determine the hemagglutination (HA) activity of the HA subtypes. The entire genomes of the viruses were sequenced on an ABI PRISM 3500xl DNA Analyzer. The sequences were genetically analysed to study their genetic evolution using DNASTAR and MEGA 6. The pathogenic effects of the viruses were evaluated using mouse infection models. RESULTS: Seven strains of the H1 subtype avian influenza virus were isolated. Phylogenetic analysis indicated natural recombination of the H1 influenza viruses between the Eurasian lineage and the North American lineage. Some genes had high sequence identity with A/bean goose/Korea/220/2011(H9N2), which is a typical case involving viral reassortment between the Eurasian lineage and the North American lineage. The results of infection experiments in mice showed that the viruses could acquire the ability to multiply in mouse respiratory organs without adaptation. CONCLUSIONS: These findings suggest that continued surveillance of wild birds, particularly migratory birds, is important to provide early warning of possible H1 influenza epidemics and to understand the ecology of the virus.

Primary survey of avian influenza virus and Newcastle disease virus infection in wild birds in some areas of Heilongjiang Province, China.

Two hundred thirty specimens of wild birds were collected from some areas in Heilongjiang Province during the period of 2003-2004, including two batches of specimens collected randomly from a same flock of mallards in Zhalong Natural Reserve in August and December, 2004, respectively. Primary virus isolation and identification for avian influenza virus (AIV) and Newcastle disease virus (NDV) were performed. The results showed that only two specimens of young mallards collected from Zhalong Natural Reserve in August, 2004 were positive to AIV (isolation rate 0.9%), and one strain (D57) of these two virus isolates was identified to be H9 subtype by hemagglutination inhibition test. Meanwhile, the two batches of blood serum samples of mallards from Zhalong were also examined for antibodies against AIV and NDV. Among 38 blood serum samples collected in August, antibodies against the hemagglutinin of H1, H3, H5, H6 and H9 subtypes of AIV were found in 1, 0, 2, 0 and 8 samples, respectively; and 11 samples were found with antibody against NDV. Whereas the NDV isolation in both two batches of specimens of mallard was negative, all of the 32 blood serum samples collected in December were negative for antibodies against AIV and NDV.

Establishment of reverse transcription loop-mediated isothermal amplification for rapid detection and differentiation of canine distemper virus infected and vaccinated animals.

Although widespread vaccination against canine distemper virus (CDV) has been conducted for many decades, several canine distemper outbreaks in vaccinated animals have been reported frequently. In order to detect and differentiate the wild-type and vaccine strains of the CDV from the vaccinated animals, a novel reverse transcription loop-mediated isothermal amplification (RT-LAMP) method was developed. A set of four primers-two internal and two external-were designed to target the H gene for the specific detection of wild-type CDV variants. The CDV-H RT-LAMP assay rapidly amplified the target gene, within 60 min, using a water bath held at a constant temperature of 65°C. The assay was 100-fold more sensitive than conventional RT-PCR, with a detection limit of 10(-1)TCID50ml(-1). The system showed a preference for wild-type CDV, and exhibited less sensitivity to canine parvovirus, canine adenovirus type 1 and type 2, canine coronavirus, and canine parainfluenza virus. The assay was validated using 102 clinical samples obtained from vaccinated dog farms, and the results were comparable to a multiplex nested RT-PCR assay. The specific CDV-H RT-LAMP assay provides a simple, rapid, and sensitive tool for the detection of canines infected with wild-type CDV from canines vaccinated with attenuated vaccine.

Temporal and spatial expression of AIF in the mouse uterus during early pregnancy.

Apoptosis-inducing factor (AIF) is a phylogenetically old, bifunctional protein with a pro-apoptotic function and redox activity. AIF regulates apoptosis and also plays a role in the defense against stress depending on its subcellular localization. Embryo implantation is a complicated process, in which an activated blastocyst interacts with a receptive uterus. The expression and regulation of AIF were investigated in this study in the mouse uterus during early pregnancy, pseudopregnancy, delayed implantation, artificial decidualization and under hormonal treatment using in situ hybridization, immunohistochemistry and real-time PCR. During early pregnancy, temporally and spatially regulated patterns of AIF expression were found in the mouse uterus; AIF expression in the luminal epithelium and glandular epithelium is regulated by steroid hormones; AIF mRNA expression in the stroma is influenced by the active blastocyst; and AIF protein was found to be located in the cytoplasm rather than the nucleus through confocal microscope. Our data suggest that AIF might play an important role during mouse embryo implantation and that the role of AIF might be implemented through its physiological activity rather than through its pro-apoptotic function in the mouse uterus during this period.